Fix get_table_stats row counts

[pbourdon71]

Summary

get_table_stats was reporting cumulative row activity instead of live row counts. The implementation used n_tup_ins + n_tup_upd + n_tup_del, which grows with churn and diverges from both COUNT(*) and n_live_tup.

This changes row_count to use COALESCE(n_live_tup, 0)::bigint in both getTableStatsTool queries and tightens the integration test to assert the expected fixture row count.

Validation

• npm run build
• npm test -- --runTestsByPath tests/integration/container.test.ts

Notes

I reproduced the bug against a live PostgreSQL database before patching:

• exact COUNT(*) on players: 34475
• pg_stat_user_tables.n_live_tup: 34475
• get_table_stats row_count before fix: 365631